Contact-finger and base



I. DEUTSCH.-

QONTACT FINGER AND BASE. "memo-n min man. 1914. RENEWED re s. 13.1918.

Patented Sept. 16, 1919.,

:- ;|NVENTOR ATTORNEY wnNrzsses:

rut: COLUMBIA PLANOORAPII an, WASHINGTON, n. c

UNITED STATIJEO PATENT OFFICE.

ISIDOER. DEUTSCI-I, 0F CINCINNATI, OHIO, ASSTGNOR T0 WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

CONTACT-FINGER AND BASE.

1,315,950. Application filed February 21,

To all whom it may concern:

Be it known that I, Ismo-R Dno'rsori, a citizen of the United States,and a resident of Cincinnati, in the county of Hamilton and State ofOhio, have invented a new and useful Improvement in Contact-Fingers andBases, of which the following is a specification.

My intention relates to contact fingers and bases therefor which areadapted for use in connection with controllers of the drum type andsimilar circuit-controlling mechanisms.

My invention has for its object to provide a means whereby the cont-actfingers and related parts of controlling mechanisms may be protected(from damage that may be caused by abnormal stresses upon the same.

A contact finger, as commonly con structed, comprises a contact elementwhich is mounted upon the free end of a blade spring, the other end ofthe spring being fixed to a relatively stationary part. It may occur inthe operation of control mechanism, .that the engaging surfaces of thecontactsegments or of the contact fingers may become toughened or pittedas a result of arcs which follow the opening and closing of thecontrolled circuits. Under these conditions, movement of the segments orof the contact lingers may cause the parts to firmly engage. When therelative movement of the controller drum is toward the point of supportof the contact finger, the result has been, ordinarily, to cause thesupporting spring to buckle until the parts become disengaged. Thespring, if not broken, may be permanently distorted so that the contactfinger will not engage the coacting contact segments with the properpressure or at the proper point in the relative angular movement ofthese parts. As is Well known, it is highly desirable in the interest ofsafe operation, that each part of a controller should perform its properfunction at all times.

In carrying out my invention, I employ a base member which supports thecontact finger and which is provided with means for taking up the thrustupon the contact finger should the latter be caught by the roughenedsurface of the contact segments as above described. By means of thisarrangement, I effectually prevent injury to Specification of LettersPatent.

1914, Serial No. 820,217. Renewed February 13, 1918. Serial No. 216,942.

the supporting spring and thus avoid the delay and expense incident tothe repair or replacement of the damaged parts,

In the accompanying drawing, the single figure 1s a side view, inelevation, of a base and contact finger, the supporting member beingshown in section.

A base member 1, of irregular shape, is provided with a rectangularopening 2 to receive a supporting arm3. The base member 1 is providedwith a slit 4% to provide a means for clamping the base member to thearm 3 by means of a clamping screw 5. A second slit 6 and a clampingscrew 7 provlde a means for rigidly clamping a pair of spr1ngs'8 and 9,of phosphor bronze or similar material. The spring 9 is provided with anintermediate curved portion 10, to render the springs more rigid at thispoint. A contact finger 11 is attached to the free end of the spring 8by means of a bolt l2. A lug 13, which is integral with the base member1, is provided with an opening it in which the bolt 12 may reciprocateto act as a guide for and to limit the movement of the contact finger11.

The base member 1 is provided with a shoulder 1.5 which is normallyseparated by a small space from the end 16 of the contact finger 11.Should the controller drum 17 a portion of which is indicated by dot anddash, lines, be moved in the direction of the arrow and the finger 11 beengaged by a roughened surface on the drum to carry the finger in thesame direction, the end portion 16 of the finger will engage theshoulder 15 after a slight endwise movement. The springs 8 and 9 will,therefore, be bent only slightly, the thrust being substantiallyentirely taken up by the shoulder 15. The curved portion 10 of thespring 9' prevents the springs 8 and 9 from being broken or distorted bydistributing the stress tending to bend the springs at their middlepoint. The only damage that can result, under the circumstances abovedescribed, is to bend the finger 11, and that only in the infrequentinstances in which the engaging parts do not move relatively after aconsiderable thrust has been applied to the contact finger. When thedrum rotates in a direction opposite to the arrow, no damage can resultto the contact finger and its related parts as the force is applied tothe finger in a direction away from the point of support of the springs8 and 9 and at an angle 'to a line passing therethrough, thus permittingthe finger to move laterally to be disengaged from the drum.

I claim as my invention:

1. The combination With a base member having a shoulder portion, of acontact ele ment resiliently supported by said base member and having aportion adjacent said shoulder portion to coact therewith, and means forguiding relative movements of the base member and the contact element.

2. The combination with a base member having an integral shoulderportion, of a contact element having a portion to engage said shoulderportion at the end of a' predetermined movement thereof, a supportingspring mounted on said base member, and a unitary means for clampingsaid contact element to its supporting spring and for gulding themovements thereof.

3. The combination with a base member, a contact element, and aresilient supporting means secured to .the base member, of a singlemeans for clamping the contact element to its supporting means and forlimiting the movements of the contact element.

4. The combination with a base member, of a blade spring attached at oneend to said base member and provided with an intermediate curvedportion, a contact element, means for clamping said contact element tothe blade spring, said means also serving to limit and guide therelative movements of the contact element and the base member, and meansintegral with said base member for engaging the contact element at theend of a predetermined relative movement.

5. The combination with a base member having a projection, of a contactelement resiliently supported by said base member and having a portionadjacent said projection for engagement therewith at the end of apredetermined relative movement, and means for limiting and guiding therelative movements of the several parts.

6. The combination with a base member having a stop portion, a contactelement, and a support therefor, said contact element being resilientlyheld in operative position, of a single means for clamping said 'contactelement to its support and for engaging said stop portion to limitrelative movements of said contact element and said base member.

7. The combination with a base member having an opening, a blade springsecured to said base member, and a contact element carried by saidspring, of a bolt located in said opening, said bolt alone clamping saidcontact element to said spring, the'head of said bolt engaging said basemember to limit the forward movement of said contact element.

8. The combination with a base member having a shoulder portionjvhich isimmovable with respect to said base member, of a contact elementresiliently supported by said base member and having aportion adapted toengage said shoulder portion at the end of a predetermined relativemovement.

9. The combination with a base member having a shoulder portion at oneend, of a pair of blade springs attached at the other end and extendingtoward said one end, the blade spring which is farthest removed fromsaid shoulder portion being provided with an intermediate curvedportion, and a contact element secured to said blade springs at theirfree ends and having a portion for cooperating with said shoulderportion.

10. In a controller, a support, a resilient member carried thereby, acontact finger secured to said member, a stop secured to said supportfor limiting the degree of movement of said finger in one direction, andmeans for limiting the degree of movement of said finger in the oppositedirection.

11. In a controller, the combination with a support, a resilient membersecured thereto and a contact finger mounted'on said resilient member,of a stop member secured to said support and provided with an opening, abolt located in said opening, the head of said bolt engaging said stopto limit the degree ofmovement of said finger, and means for lockingsaid bolt in adjusted position.

In testimony whereof, I have hereunto subscribed my name this 14th dayof F ebruary, 1914.

ISIDOR DEUTSOH.

IVitnesses:

F. IV. LERSCH, H. C. AL'rnMnIER.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents,

. Washington, D. 0.

